Bieber duets with Craig David at the O2

Justin Bieber promised his London audience some surprises and pulled out all the stops after bringing UK R&B sensation Craig David out onto the stage with him.

The 'Baby' singer revealed he was a fan of David's during his UK premiere of 'Never Say Never 3D' where the pair initially met, and he joined Bieber onstage last night (March 14) to perform 'Seven Days'.

The teen star is also set to return to London's O2 Arena tomorrow night, March 16 and then on Thursday, March 17. Watch his live collaboration with Craig David here: